.mj{
    width: 600px;height: 400px;
    background: #e8e2e2;
    display: flex;
    margin: 0 auto;
}
.mj div{
    border:#dc3232 solid 2px;
}
.flex1{
    flex: 1;
    background-color: aqua;
}
.flex2{
    flex: 2;
    /* width: 100px; */
    background-color: blue;
}